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Apparatus for detecting defects in pattern

  • US 4,589,139 A
  • Filed: 01/31/1983
  • Issued: 05/13/1986
  • Est. Priority Date: 02/04/1982
  • Status: Expired due to Fees
First Claim
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1. An apparatus for inspecting a pattern consisting of bright parts and dark parts formed on a planar test speciment based upon design data, said apparatus comprising:

  • an imaging means for scanning the pattern to generate binary signals according to the pattern;

    a first extracting means for serially extracting from the binary signal binary information corresponding to a determined area on the test specimen;

    a detecting means for generating a detection output upon detecting a specific shape in the determined area on the basis of the binary information, the specific shape having a boundary line between the bright parts and the dark parts of the pattern, the boundary line including a first line shorter than the width of the determined area and two parallel lines respectively extending from the ends of the first line, respectively, in opposite directions;

    a second extracting means for extracting information about the specific shape which the pattern is expected to have, from the design data with relation to the location of the determined area;

    an inspecting means for checking the detection output with the information extracted by the second extracting means.

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